Frontline Top Spot for Dogs is a monthly treatment for controlling and preventing fleas and ticks in dogs. The spot-on treatment removes external parasite such as fleas, ticks and chewing lice found in dogs. It impedes the growth of these parasites by killing their all life stages and prevents re-infestation. Frontline Top Spot contains Fipronil as its active ingredient which has adulticidal properties to kill adult fleas and ticks by paralyzing their nervous system. It destroys the newly hatched adult fleas before they lay eggs and prevents its re-infestation.